A wholistic RSS namespace for podcasting that is meant to synthesize the fragmented world of podcast namespaces. As elements are canonized, they will be added to this document so developers can begin implementation. The specifications below are considered locked and the team will prioritize backward compatibility. We are operating under the [Rules for Standards-Makers](http://scripting.com/2017/05/09/rulesForStandardsmakers.html).
The namespace for this extension is `https://podcastindex.org/namespace/1.0`. Clients which recognize this namespace must also recognize `https://github.com/Podcastindex-org/podcast-namespace/blob/main/docs/1.0.md` as identical. The suggested tag prefix for use in XML is `podcast`, but clients should support alternate prefixes for this namespace. If your application generates RSS feeds and you implement one or more elements below, you will need to link this document in your XML:
- **language (optional):** The language of the linked transcript. If there is no language attribute given, the linked file is assumed to be the same language that is specified by the RSS `<language>` element.
- **rel (optional):** If the rel="captions" attribute is present, the linked file is considered to be a closed captions file, regardless of what the mime type is. In that scenario, time codes are assumed to be present in the file in some capacity.
This tag may be set to `yes` or `no`. The purpose is to tell other podcast hosting platforms whether they are allowed to import this feed. A value of `yes` means that any attempt to import this feed into a new platform should be rejected.
- **owner (optional):** The owner attribute is an email address that can be used to verify ownership of this feed during move and import operations. This could be a public email or a virtual email address at the hosting provider that redirects to the owner's true email address.
This is a free form string supplied by the creator which they expect to be displayed in the app next to the link. Please do not exceed `128 characters` for the node value or it may be
Links to an external file (see example file) containing chapter data for the episode. See the [jsonChapters.md](https://github.com/Podcastindex-org/podcast-namespace/blob/main/chapters/jsonChapters.md) file for a description of the chapter file syntax. And, see the [example.json](https://github.com/Podcastindex-org/podcast-namespace/blob/main/chapters/example.json) example file for a real world example.
Benefits with this approach are that chapters do not require altering audio files, and the chapters can be edited after publishing, since they are a separate file that can be requested on playback (or cached with download). JSON chapter information also allows chapters to be displayed by a wider range of playback tools, including web browsers (which typically have no access to ID3 tags), thus greatly simplifying chapter support; and images can be retrieved on playback, rather than bloating the filesize of the audio. The data held is compatible with normal ID3 tags, thus requiring no additional work for the publisher.
Points to one or more soundbites within a podcast episode. The intended use includes episodes previews, discoverability, audiogram generation, episode highlights, etc. It should be assumed that the
audio/video source of the soundbite is the audio/video given in the item's [`<enclosure>`](https://cyber.harvard.edu/rss/rss.html#ltenclosuregtSubelementOfLtitemgt) element.
This is a free form string from the podcast creator to specify a title for the soundbite. If the podcaster does not provide a value for the soundbite title, then leave the value blank, and podcast apps can decide to use the episode title or some other placeholder value in its place. Please do not exceed `128 characters`
This element specifies a person of interest to the podcast. It is primarily intended to identify people like hosts, co-hosts and guests. Although, it is flexible enough to allow fuller credits to be given using the roles and groups that are listed in the [Podcast Taxonomy Project](https://podcasttaxonomy.com/)
It is suggested that `<channel>` is always populated, and `<item>` is populated where needed for an individual episode. Where present, people information in `<item>` wholly replaces all information from the `<channel>`.
Publishers are expected to use the `podcast:person` element in the `<channel>` parent to set the _regular_ people involved in the podcast: the detail that would be expected to be seen in an overview of the show.
The fictional podcast _Terry and June_ is normally hosted by Terry Scott and June Whitfield. Within `<channel>`, Terry Scott and June Whitfield are listed as the hosts. A podcast directory, or podcast app, should show Terry Scott and June Whitfield as the hosts of this show.
For one episode, _Terry and June_ was hosted by Reginald Marsh and June Whitfield (Terry was away). In this case, the `<item>` for this episode should contain Reginald Marsh and June Whitfield as the hosts of this episode. A podcast app, when playing this episode, should show only Reginald Marsh and June Whitfield as the hosts of this episode. Because people information in `<item>` replaces all existing people information in `<channel>`, Terry Scott should not be visible as a host of this episode.
#### For example: _Big Daddy_
The fictional podcast _Big Daddy Interviews_ is hosted by Big Daddy, a wrestler. Within `<channel>`, Big Daddy is listed as the host. A podcast directory, or podcast app, should show Big Daddy as the host of this show.
For one episode, _Big Daddy Interviews_ had a guest of Sid James. In this case, the `<item>` for this episode should contain Sid James as a guest, **and** Big Daddy as the host of this episode. Because people information in `<item>` replaces all existing people information in `<channel>`, Big Daddy should be re-stated as the host of this episode.
This is the full name or alias of the person. This value cannot be blank. Please do not exceed `128 characters` for the node value or it may be truncated by aggregators.
- **role:** (optional) Used to identify what role the person serves on the show or episode. This should be a reference to an official role within the Podcast Taxonomy Project list (see below). If `role` is missing then "host" is assumed.
- **group:** (optional) This should be a reference to an official group within the Podcast Taxonomy Project list. If `group` is not present, then "cast" is assumed.
- **href:** (optional) The url to a relevant resource of information about the person, such as a homepage or third-party profile platform. Please see the [example feed](https://github.com/Podcastindex-org/podcast-namespace/blob/main/example.xml) for possible choices of what to use here.
The `role` and `group` attributes are case-insensitive. So, "Host" is the same as "host", and "Cover Art Designer" is the same as "cover art designer".
This tag is intended to describe the location of editorial focus for a podcast's content (i.e. "what place is this podcast about?"). The tag has many use cases and is one of the more complex ones. You
are **highly encouraged** to read the full [implementation document](https://github.com/Podcastindex-org/podcast-namespace/blob/main/location/location.md) before starting to code for it.
This is a free-form string meant to be a human readable location. It may conform to conventional location verbiage (i.e. "Austin, TX"), but it shouldn't be depended on to be parseable in any specific
way. This value cannot be blank. Please do not exceed `128 characters` for the node value or it may be truncated by aggregators.
- **name:** (optional) - This is the "name" of the season. If this attribute is present, applications are free to **not** show the season number to the end user, and may use it simply for chronological sorting and grouping purposes.
This element exists largely for compatibility with the `season` tag. But, it also allows for a similar idea to what "name" functions as in that element.
- **display:** (optional) - If this attribute is present, podcast apps and aggregators are encouraged to show its value instead of the purely numerical node value. This attribute is a string.
The episode numbers are decimal, so numbering such as `100.5` is acceptable if there was a special mini-episode published between two other episodes. In that scenario, the number would help with proper
chronological sorting, while the `display` attribute could specify an alternate special "number" (a moniker) to display for the episode in a podcast player app UI.
This element is used to define the location of an audio or video file to be used as a trailer for the entire podcast or a specific season. There can be more than one trailer present in the channel of the
feed. This element is basically just like an [`<enclosure>`](https://cyber.harvard.edu/rss/rss.html#ltenclosuregtSubelementOfLtitemgt) with the extra `pubdate` and `season` attributes added.
If there is more than one trailer tag present in the channel, the most recent one (according to its `pubdate`) should be chosen as the preview by default within podcast apps.
The node value is a string, which is the title of the trailer. It is required. Please do not exceed `128 characters` for the node value or it may be truncated by aggregators.
If the `season` attribute is present, it must be a number that matches the format of the `<podcast:season>` tag. So, for a podcast that has 3 published seasons, a new `<podcast:trailer season="4">` tag can
be put in the channel to later be matched up with a `<podcast:season>4<podcast:season>` tag when it is published within a new `<item>`.
This element defines a license that is applied to the audio/video content of a single episode, or the audio/video of the podcast as a whole. Custom licenses must always include a url attribute. Implementors are encouraged
to read the license tag companion [document](https://github.com/Podcastindex-org/podcast-namespace/blob/main/proposal-docs/license/license.md) for a more complete picture of what this tag is intended to accomplish.
The node value must be a lower-cased reference to a license "identifier" defined in the [SPDX License List](https://spdx.org/licenses/) file if the license being used is a well-known, public license. Or, if it is a custom license, it
must be a free form abbreviation of the name of the license as you reference it publicly. Please do not exceed `128 characters` for the node value or it may be truncated by aggregators.
- **url:** (optional) This is a url that points to the full, legal language of the license being referenced. This attribute is optional for well-known public licenses. For new, or custom licenses it is required.
This element is meant to provide different versions of, or companion media to the main [`<enclosure>`](https://cyber.harvard.edu/rss/rss.html#ltenclosuregtSubelementOfLtitemgt) file. This could be an audio only version of a video podcast to allow apps to switch back and forth between audio/video,
lower (or higher) bitrate versions for bandwidth constrained areas, alternative codecs for different device platforms, alternate URI schemes and download types such as IPFS or WebTorrent, commentary tracks or supporting source clips, etc.
This is a complex tag, so implementors are highly encouraged to read the companion [document](https://github.com/Podcastindex-org/podcast-namespace/blob/main/proposal-docs/alternateEnclosure/alternateEnclosure.md) for a fuller understanding of how
The node value must be one or more `<podcast:source>` elements that each define a uri where the media file can be downloaded or streamed. A single, optional `<podcast:integrity>` element may also be included
- **height:** (optional) Height of the media asset for video formats.
- **lang:** (optional) An [IETF language tag (BCP 47)](https://en.wikipedia.org/wiki/BCP_47) code identifying the language of this media.
- **title:** (optional) A human-readable string identifying the name of the media asset. Should be limited to 32 characters for UX.
- **rel:** (optional) Provides a method of offering and/or grouping together different media elements. If not set, or set to "default", the media will be grouped with the enclosure and assumed to be an alternative to the enclosure's encoding/transport. This attribute can and should be the same for items with the same content encoded by different means. Should be limited to 32 characters for UX.
- **codecs:** (optional) An [RFC 6381](https://tools.ietf.org/html/rfc6381) string specifying the codecs available in this media.
- **default:** (optional) Boolean specifying whether or not the given media is the same as the file from the enclosure element and should be the preferred media element. The primary reason to set this is to offer alternative transports for the enclosure. If not set, this should be assumed to be false.
This element defines a uri location for a `<podcast:alternateEnclosure>` media file. It is meant to be used as a child of the `<podcast:alternateEnclosure>` element. At least one `<podcast:source>` element must be
- **contentType:** (optional) This is a string that declares the mime-type of the file. It is useful if the transport mechanism is different than the file being delivered, as is the case with a torrents.
This element defines a method of verifying integrity of the media given either an [SRI-compliant integrity string](https://www.w3.org/TR/SRI/) (preferred) or a base64 encoded PGP signature. This element is optional within a
`<podcast:alternateEnclosure>` element. It allows to ensure that the file has not been tampered with.
This element is used to declare a unique, global identifier for a podcast. The value is a UUIDv5, and is easily generated from the RSS feed url, with the **protocol scheme and trailing slashes stripped off**, combined with a unique "podcast" namespace which has a UUID of `ead4c236-bf58-58c6-a2c6-a6b28d128cb6`. Tools like [this one](https://www.uuidtools.com/v5) can help generate these values by hand. Or, language libraries like [this one](https://github.com/sporkmonger/uuidtools) in Ruby are widely available.
A podcast gets assigned a podcast:guid once in its lifetime using its current feed url (at the time of assignment) as the seed value. That GUID is then meant to follow the podcast from then on, for the duration of its life, even if the feed url changes. This means that when a podcast moves from one hosting platform to another, its podcast:guid should be discovered by the new host and imported into the new platform for inclusion into the feed.
* Be aware that Amazon Music also uses separate UUIDv5 identifiers within their podcast directory, which are calculated differently and unrelated to this specification.
A working example is https://podnews.net/podcast/i8xe9/listen#fastfollow-podcast:9b024349-ccf0-5f69-a609-6b82873eab3c or the QR code given below.
When scanned on a mobile phone's camera app, this link will go to the specified podcast website. Behavior of this website is up to the creator: some may use a default homepage, others may sniff the useragent and open a default podcast app on a device. In the working example, above, an iPhone user may be taken to Apple Podcasts; an Android user may be taken to Google Podcasts; and another device will be given a page with a player.
When scanned on a QR code reader inside a podcast app, like [CurioCaster](https://curiocaster.com/), the app can parse the `podcast:guid` value from the URL, allowing the podcast to be opened within the application.
This element designates the cryptocurrency or payment layer that will be used, the transport method for transacting the payments, and a suggested amount denominated in the given cryptocurrency.
This element can exist at either the `<channel>` or `<item>` level. When it exists at the `<item>` level, it should be treated as an "override" of whatever is defined at the `<channel>` level.
This is a complex tag, so implementors are HIGHLY encouraged to read the companion [document](https://github.com/Podcastindex-org/podcast-namespace/blob/main/value/value.md) for a complete understanding of how
The `valueRecipient` tag designates various destinations for payments to be sent to during consumption of the enclosed media. Each recipient is considered to receive a "split" of the total payment according to the number of shares given
in the `split` attribute.
This element may only exist within a parent `<podcast:value>` element.
There is no limit on how many `valueRecipient` elements can be present in a given `<podcast:value>` element.
This is a complex tag, so implementors are HIGHLY encouraged to read the companion [document](https://github.com/Podcastindex-org/podcast-namespace/blob/main/value/value.md) for a complete understanding of how
The `medium` tag tells the an application what the content contained within the feed IS, as opposed to what the content is ABOUT in the case of a category. This allows a podcast app to
modify it's behavior or UI to give a better experience to the user for this content. For example, if a podcast has `<podcast:medium>music</podcast:medium>` an app may choose to
reset playback speed to 1x and adjust it's EQ settings to be better for music vs. spoken word.
Accepted medium names are curated within a list maintained by the community as new mediums are discovered over time. Newly proposed mediums should require some level of
justification to be added to this list. One may argue and/or prove use of a new medium even for only one application, should it prove different enough from existing mediums to have meaning.
-`film` - Specific types of videos with one item per feed. This is different than a `video` medium because the content is considered to be cinematic; like a movie or documentary.
This tag, when present, allows for specifying many different image sizes in a compact way at either the episode or channel level. The syntax is borrowed from
the HTML5 [srcset](https://html.spec.whatwg.org/multipage/images.html#srcset-attributes) syntax. It allows for describing multiple image sources with width and
pixel hints directly in the attribute. Although the HTML5 `srcset` attribute allows relative urls, absolute urls are required in this tag - since the feed url may not represent an appropriate base url for relativization.
- **srcset** (required) A string that denotes each image url followed by a space and the pixel width, with each one separated by a comma. See the example
The `liveItem` tag is used for a feed to deliver a live audio or video stream to podcast apps. It takes the same format as a standard `<item>` episode tag, and all tags that are
allowed as children of a normal `<item>` are also allowed as children of `<podcast:liveItem>`. Note that "allowed" is not the same as "supported". So, just like a normal `<item>`,
you cannot depend on all apps to support all tags within `<podcast:liveItem>`, especially when the function of the tag is not obvious. For instance, including an `<itunes:duration>`
This tag will also make use of the [podping](https://podping.cloud) notification network. A podping notification SHOULD be sent out by the host when the live stream starts, to let
When specifying the audio/video source, the [`<podcast:alternateEnclosure>`](#alternate-enclosure) tag is highly encouraged since it gives the broadest coverage of possible stream types and is
explicit in it's communication of what transport protocol and media codecs are being used. In addition to [`<podcast:alternateEnclosure>`](#alternate-enclosure), a standard [`<enclosure>`](https://cyber.harvard.edu/rss/rss.html#ltenclosuregtSubelementOfLtitemgt) should also
be given as a fallback to support podcast apps that don't yet implement [`<podcast:alternateEnclosure>`](#alternate-enclosure). Regardless of which enclosure tag is used, feed owners must be conscious
of the fact that choosing a non-mainstream streaming protocol/codec will limit the number of apps that can play the content. For that reason, it's highly recommended to use only the two most widely supported
protocols (mp3 and mp4/h.264) to ensure compatibility with the broadest number of apps on various platforms. Choosing a streaming format that is outside of this narrow list might exclude many
apps from playing your content. As broader adoption of HLS, Opus, etc. becomes apparent, this recommendation will change to include newer formats.
The [`<podcast:contentLink>`](#content-link) tag is also required to be present, to ensure that listeners have a fallback option in case their chosen app cannot play the given content stream directly. In
most instances this will just be a link to an HTML page that can play the live stream. Such a page can reside on the podcaster's own website, a page provided by their hosting company or a third party
platform they have chosen to use. Podcasters who live stream to multiple platforms at once can also use the [`<podcast:contentLink>`](#content-link) tag to provide links to those other platforms.
A robust, well-written `<podcast:liveItem>` tag will include all three of: [`<podcast:alternateEnclosure>`](#alternate-enclosure), [`<enclosure>`](https://cyber.harvard.edu/rss/rss.html#ltenclosuregtSubelementOfLtitemgt)
and [`<podcast:contentLink>`](#content-link) to ensure the broadest interopability with podcast apps.
The function of `<guid>` within a live item tag is the same as it is within a regular item. If the `<guid>` of a `<podcast:liveItem>` changes, it MUST be considered a new stream by
The `start` and `end` attributes denote when the live stream "should" start and end. But, real life dictates that those times might not be adhered to. Apps are therefore encouraged
not to rely solely on those times as anything more than an approximation. The canonical way to know if a stream has started is with the `status` attribute. If `status` is "live" then
instead of, or in addition to, being delivered directly to the tag itself within an app. In most instances it is used as a fallback link for the user
to use when the app itself can't handle a certain content delivery directly.
For instance, perhaps a podcast feed specifies a `<podcast:liveItem>` to deliver a live stream to apps. The feed may also give a `<podcast:contentLink>`
pointing to YouTube and Twitch versions of the live stream as well, just in case the listener uses an app that doesn't fully support live streaming content.
Currently this tag is only indicated for use in the `<podcast:liveItem>` tag. In the future, its use will be expanded.
### Parent
`<podcast:liveItem>`
### Count
Multiple
### Node Value
The node value is a free form string meant to explain to the user where this content link points and/or the nature of it's purpose.
### Attributes
- **href** (required) A string that is the uri pointing to content outside of the application.
### Examples
```xml
<podcast:contentLinkhref="https://youtube.com/blahblah/livestream">Live on YouTube!</podcast:contentLink>
```
```xml
<podcast:contentLinkhref="https://twitter.com/statuses/somepost">Chat on Twitter!</podcast:contentLink>
This element holds free-form text and is modeled after the DNS "[TXT](https://en.wikipedia.org/wiki/TXT_record)" record. It's meant to allow for usages that might be
niche or otherwise not rise to the level of needing a dedicated tag. Just like TXT records in DNS allowed for new things
like [SPF](https://en.wikipedia.org/wiki/Sender_Policy_Framework#Implementation) to evolve, this tag can allow novel techniques to be created and sandboxed without a formalization process.
### Parent
`<channel>` or `<item>`
### Count
Multiple
### Attributes
- **purpose** (optional) A service specific string that will be used to denote what purpose this tag serves. This could
be something like "example.com" if it's a third party hosting platform needing to insert this
data, or something like "verify", "release" or any other free form bit of info that is
useful to the end consumer that needs it. The free form nature of this tag requires that this
attribute is also free formed. This value should not exceed `128 characters`.
### Purposes
The following are a list of strings known to be in common use. This list is in no way exhaustive. As new purposes come into
common use, this list will be updated by the community to reflect that.
-`verify` - The node value is expected to contain a string that is given by a third party platform to a podcaster in
order to prove that they are the owner of the feed and are in control of it. This is meant to replace the
need for emails to exist in feeds.
### Node value
This is a free form string. Please do not exceed `4000 characters` for the node value or it may be truncated by
